• Journal of the Korean Ceramic Society
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• v.32 no.10
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• pp.1212-1218
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• 1995

Al2O3-coated SiC composite powder and mechanically mixed Al2O3-SiC composite powder were synthesized using Al-isopropoxide and commercial SiC as the starting materials. Experiment results showed that the sinterability of Al2O3-coated SiC composite powder was more improved than the mechanically mixed Al2O3-SiC composite powder by the effect of homogeneous coating of alumina around SiC particles. Hence, the mechanical properties of the former was also much more improved than the latter.

• Korean Journal of Crystallography
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• v.1 no.1
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• pp.19-28
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• 1990

6H-SiC is a promising material (Eg=3.0eV) for blue light-emitting doide and high-temperature semiconducting device. In the experiment, single crystals of a-SiC have been grown by the sublimation method to fabricate blue light~emitting diode. During the growth of a-SiC single crystals, a temperature Vadient, yonh temperature and pressure ranges were kept 44℃/cm , 1800-1990℃ and 50-1000 mTorr, respectively. Single crystals obtained in Acheson furnace were used as seed crystals. Polarizing microscopy and back-reflection X-ray Laue diffraction showed that the a-SiC crystal was epitaxially and on the seed crytal. It was found by XRD analysis that when other growth conditions were the same, a-SiC was grown at the temperature above 1840℃ and 3C-SiC was gown at lower temperature or under low supersaturation of vapor. The carrier type. concentration and mobility were measured be hole(p-type), 7.6x1014cm-3 and 19cm2V-1sec-1, respectively, by van der Pauw method.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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• pp.83-85
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• 2008

4성분계 Ti-Si-C-N 코팅막은 $TiCl_4$, $SiH_4$, $CH_4$, Ar, 그리고 $N_2$ 가스 혼합체를 이용하여 RF-PECVD 기법에 의해 Si 와 AISI 304 기판위에 합성하였다. Ti-C-(0.6)-N(0.4) 조성의 코팅막에 Si를 첨가함으로 Ti(C,N) 결정질은 줄어들고, Si3N4 및 SiC 비정질상이 나타났다. Ti-Si(9.2 at.%)-C-N의 조성에서 나노 크기의 nc-Ti(C,N) 결정질을 비정질 a-Si3N4/SiC가 둘러싸고 있는 형태의 나노 복합체를 나타내었다. 경도 24 Gpa의 Ti-C-N 코팅막은 Si를 첨가함으로 Ti-Si(9.2 at.%)-C-N 조성에서 46 Gpa의 최고 경도를 나타내었으며, 마찰계수의 경우에도 Ti-C-N 코팅막에 Si를 첨가함으로 크게 낮아졌다.

• Nuclear Engineering and Technology
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• v.51 no.3
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• pp.769-775
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• 2019

The tensile strength of irradiated 3C-SiC, SiC with artificial point defects, SiC with symmetric tilt grain boundaries (GBs), irradiated SiC with GBs are investigated using molecular dynamics simulations at 300 K. For an irradiated SiC sample, the tensile strength decreases with the increase of irradiation dose. The Young's modulus decreases with the increase of irradiation dose which agrees well with experiment and simulation data. For artificial point defects, the designed point defects dramatically decrease the tensile strength of SiC at low concentration. Among the point defects studied in this work, the vacancies drop the strength the most seriously. SiC symmetric tilt GBs decrease the tensile strength of pure SiC. Under irradiated condition, the tensile strengths of all SiC samples with grain boundaries decrease and converge to certain value because the structures become amorphous and the grain boundaries disappear after high dose irradiation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.834-837
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• 2003

In this study, Ohmic contacts make on 3C-SiC using TiN. Ohmic contact resistivity of TiN/3C-SiC was evaluated. Specific contact resistance was calculated by Circular-TLM(transmission line model) method and physics properties were measured using XRD, SEM, respectively. TiN contact is stable at high temperatures and a good diffusion barrier material. The TiN/3C-SiC contacts are thermally stable to annealing temperatures up to $1000^{\circ}C$. The TiN thin-film depostied on 3C-SiC substraes have good electrical properties. Therefore, the TiN/3C-SiC contact can be usefully applied for high-temperature MEMS applications over $500^{\circ}C$.

• Korean Journal of Materials Research
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• v.6 no.4
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• pp.421-427
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• 1996

초미립 SiC 분말을 2차상으로 Si3N4에 첨가하여 SiC/Si3N4 나노 복합체를 핫프레스법과 가스압소결고 제조하였다. 2차상으로 첨가한 SiC의 입자 크기가 $\beta$-Si3N4 나노 복합체를 제조할 수 있었다. 사온에서 80$0^{\circ}C$까지는 강도의 100$0^{\circ}C$이상에서는 강도는 급격한 감소를 보였으며 이는 소결조제로 첨가한 AI2O3, Y2O3와 SiO2가 $\beta$-Si3N4의 입계에 유리상을 형성하였기 때문에 해석된다.

• Journal of the Korean Ceramic Society
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• v.47 no.6
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• pp.560-565
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• 2010

Nano laminated bulk $Ti_3SiC_2$ was synthesized by hot press process using TiCx/Si powder mixture at the temperature range of $1300^{\circ}C\sim1500^{\circ}C$. pure $Ti_3SiC_2$ was synthesized by a hot pressing above $1400^{\circ}C$, while unreacted TiCx were remained in bulk $Ti_3SiC_2$ which synthesized below $1400^{\circ}C$. The sintering density of bulk $Ti_3SiC_2$ were varied with the amount of TiCx. It was found that the mechanical properties and micro structures of bulk $Ti_3SiC_2$ were closely related to the amounts of TiCx which was controlled by the hot pressing temperature. The TiCx increase the flexural strength of bulk $Ti_3SiC_2$, while the fracture toughness and thermal shock resistance of bulk $Ti_3SiC_2$ were decreased with the content of TiCx. The plastic deformations of bulk $Ti_3SiC_2$ were appeared above $1000^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.35 no.1
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• pp.1-4
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• 1998

SiC whisker reinforced Al2O3-SiC composite was fabricated by reaction synthesis method whish is cost ef-fective and allows good dispersion of whiskers. Fracture strength at room temperature showed the highest value with 150$0^{\circ}C$ reaction temperature because a lot of SiC whiskers was formed. Fracture strength at 135$0^{\circ}C$ did not show big differences with reaction temperature due to agglomeration of whiskers and formation of sil-icon oxynitride during hot MO(modulus of rupture) test probably promoting grain boundary sliding.

• Journal of Sensor Science and Technology
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• v.17 no.4
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• pp.256-260
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• 2008

This paper describes the mechanical properties of poly(polycrystalline) 3C-SiC thin films with various doping concentration, in which poly 3C-SiC thin fil's mechanical properties according to the n-doping concentration 1($9.2{\times}10^{15}cm^{-3}$), 3($5.2{\times}10^{17}cm^{-3}$), and 5%($6.8{\times}10^{17}cm^{-3}$) respectively were measured by nano indentation. In the case of $9.2{\times}10^{15}cm^{-3}n$-doping concentration, Young's modulus and hardness were obtained as 270 and 30 GPa, respectively. When the surface roughness according to n-doping concentrations was investigated by AFM(atomic force microscope), the roughness of poly 3C-SiC thin films doped by 5% concentration was 15 nm, which is also the best of them.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.237-237
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• 2009

Zinc oxide (ZnO) thin film was deposited on Si substrates using polycrystalline (poly) 3C-SiC buffer layer, in which the ZnO film was grown by sol-gel method. Physical characteristics of the grown ZnO film was investigated experimentally by means of SEM, XRD, FT-IR (Furier Transform-Infrared spectrum), and AFM. XRD pattern was proved that the grown ZnO film on 3C-SiC layers had highly (002) orientation with low FWHM (Full width of half maxium). These results showed that ZnO thin film grown on 3C-SiC buffer layers can be used for various piezoelectric fields and M/NEMS applications.